1. Field of the Invention
The present invention relates to signal receiving apparatus and method and a recording medium, and particularly to signal receiving apparatus and method and a recording medium which are suitably used when digital satellite broadcast signals are received and supplied to a television receiver.
2. Description of the Related Art
A digital interface defined in IEEE1394 (hereinafter merely referred to as IEEE1394 interface) is equipped to some personal computers or digital video cameras. By connecting plural electronic devices each having the IEEE1394 interface to one another through an IEEE1394 bus, digital data can be transmitted between the electronic devices at high speed, and the operations thereof can be mutually controlled. In the future, the IEEE1394 interface is expected to be equipped to electronic devices other than the personal computer and the digital video camera (for example, a set top box for a digital satellite broadcast, a television receiver, etc.).
Here, a digital satellite broadcast executed in U.S. (hereinafter referred to as DSS (Direct Satellite System)) will be described. In DSS, the broadcast is carried out in SD (Standard Definition) broadcast which provides the same level resolution as the current ground broadcasts (NTSC (National Television Standard Committee) system) and in HD (High Definition) broadcast which provides a higher resolution than the SD broadcast, and both the broadcast signals are transmitted as digital data.
Accordingly, if an IEEE1394 interface is provided to the set top box for DSS to transmit a received digital broadcast signal through the IEEE1394 bus to another electronic equipment (for example, television receiver), the broadcast signal can be prevented from being deteriorated and the transmission efficiency is enhanced.
Both the SD broadcast signal and the HD broadcast signal for DSS are digital data, however, they are different in data structure (for example, packet size, etc.). For example, the packet size is different, or a transmission method is provided for the HD broadcast signal, whereas no transmission method is provided for the SD broadcast signal in the IEEE 1394. Further, the HD broadcast signal is conformed with the next-generation television broadcast system (ATSC (Advanced Television Standard Committee) system, the digital ground broadcast) in U.S.
Accordingly, there is such a problem that it is easy to transmit the HD broadcast signal received by the set top box to the IEEE1394 bus, however, it is difficult to transmit the SD broadcast signal through the IEEE1394 bus under the state that the SD broadcast signal is kept as digital data.
Further, when a broadcast signal received by the set top box corresponds to a movie or the like, and the copyright thereof is protected, it must be prevented from being unjustly recorded at a transmission destination.